1. Field of Invention:
This invention relates to missiles. Specifically, the present invention relates to fin lock systems for missiles.
2. Description of the Related Art:
Typically, the fins of a missile must be locked during transportation on an aircraft or other launch vehicle. However, at launch time, they must be quickly unlocked to be ready for missile flight. For example, a missile carried on an F-16 aircraft has its fins locked prior to launch. When the pilot is ready to fire the missile, a signal is sent from the cockpit which starts the missile""s battery. When the cockpit has confirmation that the missile is powered, it signals the missile""s fins to unlock and wiggle to verify function. When fin release and function is confirmed, the cockpit signals the missile launcher to unlock and launch the missile.
In a combat situation, where time is critical, it is essential that the fins unlock as quickly as possible. However, the small diameter (typically 5 inches) of many missiles has been an impediment to designing a fin lock system for quick release.
Prior approaches include a complicated system employing a gas generator. To effect fin release, this prior system collects gas and distributes it through a manifold to each fin piston, which compresses to release the fin. This system has many parts and is slow, taking on the order of 70 milliseconds to unlock the fins. Also, it is difficult to maintain the pressure in the one large reservoir because of gas leaks. Accidental firings are a problem with this system, and it cannot be reused because of contamination.
Another prior approach utilizes a shear pin which fractures to unlock the fins. This system requires a high energy input from an electric motor. It is also prone to failure and debris contamination. Exploding bolts have also been used, but these suffer from contamination problems as well.
Thus, a need remains in the art for a less complex, more reliable system which can lock the fins of a small diameter missile yet quickly unlock them for launch.
The need in the art is addressed by the present invention which provides a fin lock device for a missile. The device provides a mechanism for locking a missile fin by grasping an edge of the fin and means for retracting the locking means to release the fin.
In a specific embodiment, the fin is grasped by a piston having a notch therein for receiving the fin edge. The piston is retracted to release the fin by burning a pyrotechnic powder in a cavity adjacent to the piston to fill the cavity with gas and create a pressure differential to force the piston away from the fin.